1. Field of the Invention
This invention relates to tire presses and, in particular, to a method for removing the bead seat band from a wheel rim using such presses, and a bead seat breaker tool suitable for use in the method.
2. Related Prior Art
The bead seat breaker tool of the present invention may be used in conjunction with a tire press of the type disclosed in U.S. Pat. No. 3,807,478 issued to Daniel B. Mott.
3. Brief Description of the Prior Art
Tire fitters often encounter considerable difficulty when demounting the tires of large off-highway vehicles as the beads of the tires often "grow" onto the bead seat band.
A common method employed for releasing the tire bead from the bead seat band is as follows: the tire and rim assembly is placed in a tire press (e.g. of the type disclosed in the above U.S. patent) and the top platen of the tire press is lowered until the press tooling engages the bead flange on the rim. The platen is lowered to enable the locking ring and sealing ring (between the rim and the bead seat band) to be removed. The top platen of the press is then raised and the bead seat band/bead flange/tire bead combination is lifted above the rim. One or more bead seat breaker tools are clamped onto the rim, each tool having a flange which projects outwardly from the rim to be engaged by the nose of the bead seat band. The top platen is lowered and the bead seat band engages the breaker tools, preventing further downward movement of the bead seat band. The top platen is further lowered and the bead flange pushes the tire bead free of the bead seat band. The bead seat band is removed and the tire is demounted from the rim.
During the life of the wheel, the "nose" of the bead seat band becomes corroded and may become very thin. When the nose of the bead seat band is pressed down against the breaker tools, the weakened nose may be deformed outwardly, causing the tire bead to become snagged on the bead seat band and the nose of the bead seat band may cut into the bead area of the tire. This prevents the tire from being removed from the bead seat band. If the tire press continues to push downwardly on the bead flange, the bead area of the tire may be damaged as it is stripped free from the bead seat band and the tire is no longer usable (e.g. it cannot be retreaded and remounted on the rim).